Hi ferretinafez,
I actually just posted about this yesterday, because 'diminished' periods have been a problem for me since switching medications, and lxndr was the one to reply to me about loading phases, which I didn't know about. I'm not sure my doctors (2 of them) knew about loading phases either.
I was changed from Sustanon to Nebido (called Reandron) in Australia around two months ago, with just one shot on the day when I would have had my fortnightly Sustanon shot. I haven't noticed any difference in the rate of masculinisation (voice has more or less stabilised at eight months on T; muscle development is pretty steady), but I HAVE started bleeding again, which sucks a lot because I am living in a share house while overseas.
Make sure you don't change right before long-term travel like I did. It was a stupid move. Also make sure you talk to the doctors about loading, but otherwise I'd say you'll be fine. Same as the other guys here, I love the 3-monthly gap between injections, and I've found that I've been emotionally stable on Nebido (until a nasty blast of E this month).